Method and apparatus for completing oil wells



Aug. 22, 1967 J. H HYNES 5 Sheets-Sheet 1 Original Filed Jan. '7, 1965 INVENTOR JOSEPH H H YN ES ATTORNEY J. H HYNES Aug. 22, 1967 METHOD AND APPARATUS FOR COMPLETING OIL WELLS 5 Sheets-Sheet 2 Original Filed Jan. 7 1963 ATTORNEYS Aug. 22, 1967 J. H. HYNES Original Filed Jan. '7, 1963 5 Sheets-Sheet 3 INVENTOR JOSEPH H. HYN ES ATTORNEY5 1967 J. H. HYNES 3,336,978

METHOD AND APPARATUS FOR COMPLETING OIL WELLS Original Filed Jan. 7, 1963 5 heets-Sheet 4 IN VEN TOR JOSEPH H. HYNES BY KMM NG ATTORNEKS' Aug. 22, 1967 METHOD AND APPARATUS Original Filed Jan.

FOR COMPLETING OIL WELLS J. H. HYNES 5 Sheets-Sheet INVENTOR.

J OSEPH H. H Y N E 3 United States Patent 3,336,978 METHOD AND APPARATUS FOR COMPLETING OIL WELLS Joseph H. Hynes, Ventura, Calif., assignor to Gray Tool Company, Houston, Tex., a corporation of Texas Original application Jan. 7, 1963, Ser. No. 249,796, now

Patent No. 3,289,765, dated Dec. 6, 1966. Divided and this application Dec. 5, 1966, Ser. No. 599,149

Claims. (Cl. 166-21) This is a division of my co-pending application Ser. No. 249,796 filed Jan. 7, 1963, now Patent No. 3,289,765.

This invention has reference to new and improved oil well completion equipment and methods and apparatus for setting the casing head.

The principal object of the present invention is to provide apparatus and procedure for completing the well in a more rapid and eflicient manner than heretofore known in the art.

According to one feature of this invention, the casing head and associated equipment are constructed and arranged so that they can be passed through the rotary table. The casing head and associated parts are of special construction so that it can form a connected part of a unitary lowering assembly comprising the casing string and a lowering casing nipple joined by the casing head itself, so that the casing head may be lowered through the rotary table and control equipment or mud riser to its landed position. The casing head is sealed to both the casing string and the lowering nipple so that cementing operations can be commenced as soon as the casing head is landed. By virtue of this arrangement, the rotary table need not be removed from above the well when the casing head is to be set. The casing head is constructed and arranged to be of a size less than the mud riser or other control equipment temporarily mounted on the drive pipe so that the casing and the casing head can be lowered through the mud riser and the casing immediately cemented, the mud riser then being removed while the cement is setting. The next casing or tubing head can then be attached above the first mentioned casing head but after drilling operations under pressure have been performed through control equipment which was attached to the first-mentioned casing head, and which, as customary, would then be removed after the drilling operations are performed, and prior to attachment of the next casing head as referred to. The invention contemplates a new and improved method and apparatus for mounting the casing head on the drive pipe and connecting it to the lowering nipple in sealed relation.

A further object of this invention is to provide a new and improved method for assembling the casing head directly to and between the casing and the lowering nipple. In this regard the casing head is adapted to receive a lowering bushing of new and improved construction, this bushing being adapted to receive the casing head at its lower end, preferably by a left-handed thread connection. The upper end of this bushing is adapted to receive, as by a threaded joint, a suitable lowering nipple so that the united combination of casing, bushing and lowering nipple can be passed through the rotary table.

These and still further objects, advantages, and novel features of the present invention will become evident in the specification and claims, taken in connection with the accompanying drawings. It will be understood that the invention is intended to be used in association with the equipment and following the practices and procedures described and referred to in the Watts and Hill Patent 2,766,829.

In the drawings:

FIGURE 1 is an elevation view, generally in section, showing an initial phase of the well completion with the 3,336,978 Patented Aug. 22, 1967' mud riser set on the drive about to commence;

FIGURE 2 is a view similar to FIGURE 1 showing the casing head being lowered through a rotary table for support on top of the drive pipe;

FIGURE 3 is a sectional view of the casing head positioned on top of the drive pipe with the mud riser in place during cementing operations;

FIGURE 4 is a diagrammatic view similar to FIGURE 3, but showing the mud riser and the lowering hanger removed in preparation for subsequent drilling operations;

FIGURE 5 is an elevation view partially broken out, of the completed assembly with the tubing head attached;

FIGURE 6 is an elevational section view of the casing head;

FIGURE 7 is an elevational section view of the lowering bushing;

FIGURE 8 is an enlarged, detail section view of a portion of the lowering bushing of FIGURE 7; and

FIGURE 9 is a partial sectional view of a modified embodiment of this invention.

Referring now to FIGURE 1, there is shown a drive pipe 10 which has been mounted in place in the well. A supporting hub 12 is joined to the top of the drive pipe 10. The supporting hub 12 includes a peripherally depending skirt 14 which surrounds the drive pipe and is welded thereto. The supporting hub 12 has an outwardly extending flange 16 at its upper end. Moreover, the supporting hub 12 has an inwardly extending flange 18 with an inner peripherally tapered surface 20 at its upper end, together with vertically spaced apart passages 22 to allow passage of cement therethrough during cementing operations.

A mud riser or other control equipment 24 is positioned with its lower flange 26 on the flange 16 of the supporting hub so that the latter supports the control equipment 24. This joint includes a sealing ring and clamp as indicated at 28, as disclosed in the US. patents to Watts et al., 2,766,829 and 2,766,999.

A rotary table 30 is positioned immediately above the axis of the drive pipe 10 and the control equipment 24, this table 30 being supported at the derrick floor level by any suitable means well known in the art. It will be understood that the present invention has distinct applicability to underwater drilling, in which case the mud riser 24 can extend to the surface of the water where it would be provided with suitable outlets and connections, as known in the art. The rotary table is driven in a conventional fashion through a drive train and prime mover (not shown) as is well-known in the art. The rotary table 30 has a central circular passage 32 with an enlarged square upper end 34 defining thereby a radial supporting shoulder 36 of square configuration. A master bushing 38 is supported in the central passage 32 of the rotary table 30 by an external square flange 40 at its upper end which rests on the supporting shoulder 36 of the rotary table 30. The master bushing 38 has a central, longitudinally tapered passage 42 which receives a drive bushing 44 at its upper end as by an annular recess 46, upon which the drive bushing 44 rests. A kelly 48 passes through the drive bushing 44 and is driven in the usual manner. The drilling equipment includes a drill pipe and collars 50 having a drill bit 52 at its lower end. With this arrangement, the initial drilling of the well through the drive pipe takes place in the usual manner.

After this initial drilling has been completed, the drilling equipment is raised from the well and the master bushing 38 and drive bushing 44 are removed from the rotary table 30, as best shown in FIGURE 2.

Next, a casing 54 is lowered into the drilled well through the central passage 32 of the rotary table 30 to the predetermined depth. The uppermost end of the caspipe and drilling operations ing 54 slidably receives a support plate 56 which has a bottom tapered surface 57 for nesting engagement on the tapered surface 20 of the supporting hub 12 so that the hub passages 22 are not completely blocked. The support plate 56 is operative to support a special casing head 58 of reduced outside diameter which has been joined to the uppermost end of the casing 54. In this regard, the lowering operation takes place with a lowering bushing 60, removably connected into the upper end of the casing head 58, this entire structure passing through the rotary table 30 so that the same need not be removed from its aligned position for this purpose. This casing head 58 and the supporting plate 56 are adapted to be passed through the mud riser or other control equipment 24 so that the completion need not be delayed until the control equipment 24 has been removed from the supporting hub 12. A landing joint 61 is con nected to the upper end of the lowering bushing 60. The supporting plate 56 may be of a two-part hinged type so that it could be placed and looked around the easing 54 below the rotary table, if desired.

FIGURE 6 shows the construction of the casing head 58. There is here provided a central passage 62 which is interiorly threaded at its lower end with right-handed threads 64 for engagement with the cooperative threads 65 at the upper end of the casing pipe 54. The central passage 62, continuing upwardly, has a minimum diameter 66 at its central portion, then tapers outwardly at 68 forming a hanger seat, merging with a flat portion 70. The passage 62 then tapers outwardly at 72 while another long flat portion 74 merges therewith, the upper end of this latter flat portion 74 then tapering outwardly again at 76 where the passage 62 is interiorly threaded at 78 with left-handed threads. A further outward taper 80 is provided in the passage 62 at the upper end of the threads 78, the upper end of this latter taper 80 merging with a curved annular recess 82. The upper end of this annular recess 82 terminates in a flat portion 84, the passage 62 then communicating with the upper end of the casing head 58 with an outwardly extending taper 86. This casing head 58 in FIGURE 6 is shown to have side outlet bosses 88 and 90 constructed and arranged to receive plugs (FIGURE 3), and a top flange 91.

The lowering bushing 60 in FIGURES 7 and 8 is adapted to be engaged with the left-handed threads 78 in the upper region of the central passages 62 in the casing head 58. This lowering bushing 60 has a dove-tailed recess at its lowermost end receiving an O-ring 92 which is adapted to seal against the interior of the casing head passage 62. Cooperative exterior left-handed threads 94 are carried about the lowering bushing 60 for engagement with the left-handed threads 78 in the casing head 58. Above the upper end of these threads 94 there is an annular peripheral recess 96 which, when the bushing 60 is engaged with the casing head 58, aligns itself with the annular recess 82 so that an annular chamber is formed between these two structures (FIGURE 6). An outwardly tapered surface 98 extends from the upper end of the recess 96 and here carries an O-ring 100 in a dovetailed recess for sealing engagement with the tapered surface 86 in the casing head 58. This surface 98 thence merges into an outwardly extending flange-like portion 102 of inverted U-shaped configuration, which is adapted to rest on the top of the casing head 58 when the lowering bushing 60 is joined thereto. Next, there is an inwardly tapering portion 104 at the upper end of the flange portion 102, there being provided axially inclined bores 106 which are threaded along the outer part of its length at 108 for receiving a threaded plug 110. This bore 106 then communicates with another bore 112, the bore 112 providing communication with this annular chamber defined by the aligned peripheral recess 96 in the lowering hanger 60 and the annular recess 82 in the casing head 58. This arrangement of the bores 106 and 112 thereby allows pressure-testing and the like, as is necessary to ensure a tight seal. The lowering bushing 60 has an axial passage 114 outwardly tapered at its lower end at 116 and interiorly threaded at its upper end at 118 with right-handed threads. This threaded portion 118 thus receives the landing joint 61 or other lowering equipment so that when the elements are connected, the casing head 58 can be lowered through the rotary table 30 in the manner shown in FIGURE 2.

Referring now to FIGURE 3, the casing head 58 is connected to the lowering bushing 60 wherebythe elements are lowered to the supporting hub 12. The mud riser 24 is still attached to the supporting hub 12 but this view shows the mud riser threaded to the flange 26 rather than integral therewith. The side outlet bosses 88 and are equipped with removable plugs 122, so that the head is completely sealed to permit the pressure cementing operations as now referred to.

When the elements are positioned as shown in FIG- URE 3, the cementing operations can be commenced immediately. With the landing joint 61 threaded onto the upper end of the bushing 60, cementing equipment (not shown) is mounted at the top of the lowering nipple. Cement is then introduced through the landing joint pipe 61 and on down into the casing 54 through the pressure tight bushing 60 and casing head 58. The cement flows out from the bottom end of the casing 54 in the usual fashion and upwardly between the exterior of the casing and the drive pipe 10. The passages 22 in the supporting hub 12 allow mud or water to escape, and depending upon the amount of cementing to be done, the cement blockade can be formed clear up to the top of the drive pipe 10. If the mud riser 24 or other control equipment has been removed, the mud displaced by the cement may simply flow outwardly to the pits or in the surrounding water (in submarine drilling) or it may flow upwardly through any control equipment which remains attached to discharge through suitable outlets at the top thereof.

While the cement is setting not only can the mud riser 24 be removed but also appropriate sized control equipment can be attached to the casing head 58 as is well known in the art, and drilling operations can proceed under pressure through this control equipment as is well known in the art. Thus, delays in completing the well are eliminated, as one step need not be delayed until the prior step is fully completed.

In FIGURE 4, the lowering bushing 60, and the mud riser 24 have been removed with the rotary table 30 still in place, and the cementing operations have been completed. Operations can begin immediately to flange on the appropriate control equipment (not shown). Bushings 38 and 44 can be replaced in the rotary table 30 and subsequent drilling operations can begin, using necessary control equipment all as described or referred to in Watts and Hill Patent 2,766,829.

After the drilling has been completed, the Christmas tree is then completed as shown in FIGURE 5. A second casing 137 is sealed and supported in the casing head 58 by a suitable casing hanger 138, as is well known in the art. The tubing head is connected to the upper end of the casing head 58 by a sealing ring 132 which is formed of rigid but deflectable material and is operative for transverse deflection into stressed sealing engagement with the tapered surface 86 in the casing head 58 and a similarly tapered surface 134 in the bottom of the tubing head 130. A clamp 136 joins the flanged ends of the casing head and tubing head, this joint and the procedure involved being described in detail in the Watts et al. Patents 2,766,829 and 2,766, 999. The tubing 140 is mounted within the casing 54 using a suitable tubing hanger seal 142, and a Christmas tree bonnet 144 is connected to the upper end of the tubing head 140 by a like sealing ring 132 and clamp 136 as previously described. The Christmas tree valves and fittings will be supported on the bonnet 144 as is known in the art.

As previously described, the arrangement of elements,

particularly the casing head 58 and the supporting plate 56 are such that the same may be passed through both the rotary table 30 and the mud riser 24 or other control equipment 24. The maximum diameter of these elements may vary depending on the particular conditions. For instance, the bosses 38 and 90 in the casing head 58 determine these size relationships or the upper flange 91 in the casing head under some circumstances may conform to the size relationship. The supporting plate 56 may be very close to the inside diameter of the mud riser 24 and act as a guide for the elements as they are lowered into place. Moreover, the casing head 58 may be constructed so that the upper threads 78 in the passage 62 may extend downwardly relative to the bosses 88 and 90 so that the outlets (FIGURE 3) are blocked by the lower end of the bush ing 60, thereby precluding the need for plugs 122 to block these bosses during the cementing operation.

The supporting plate 56 may be attached as by welding to the underside of the casing head 50 or remain separately movable along the casing pipe 54, as desired. A significant feature of this arrangement is the ease and flexibility of assembly with a minimum of lost time. The method may also take place in underwater operations as well as dual or multiple tubing string operations, as is apparent.

Referring now to FIGURE 9, the bushing 60 is shown to have a depending skirt 146 with an exterior O-ring 1% carried at its lower end. The interior wall 74 of the casing head bore is continuous and of substantial length so that the same is adapted to be sealed with the lowering hanger 60 below the side outlets. The exterior surface of the casing head 58 is of smooth configuration having no bosses for the side outlets, the upper flange 91 thereby constituting the largest radial size which must pass through the control equipment. The casing head 58 has opposed boss-receiving surfaces 150 surrounding the side outlets with threaded machine bolt holes 152, and an annular sealing ring receiving recess 154. Thus, after initial land has been completed through the control equipment, as described and cementing operations have been completed, the bosses 83 and 90 may be bolted to the surfaces 150 by machine bolts 156, with a sealing ring 158 carried in the recess 154.

From the foregoing description of the various embodiments of this invetnion, it is evident that the objects of this invention, together with many practical advantages are successfully achieved. While preferred embodiments of my invention have been described, numerous further modifications may be made without departing from the scope of this invention.

Therefore, it is to be understood that all matters herein set forth or shown in the accompanying drawings are to be interpreted in an illustrative and not in a limiting sense.

I claim:

1. A method for drilling, completing and cementing a well comprising: mounting a first casing head having a throughbore at the well; securing a tubular member to the first casing head so that the tubular member extends axially upwardly from the first casing head and in communication with said throughbore; drilling down into the earth through the tubular member and first casing head throughbore for a string of casing; sealingly attaching a string of easing by the upper end thereof to a second casing head having a throughbore; sealingly attaching a tubular lowering member to the second casing head so that the second casing head depends from the tubular lowering member and the tubular lowering member is in communication with the string of casing through the throughhore of the second casing head; lowering the tubular lowering member, second casing head and casing string into the well through the tubular member until the second casing head receives support from the first casing head; introducing cement into the well through the bore of the tubular lowering member, second casing head throughbore and easing string; and forcing the cement out of the bore casing string and upwardly around the exterior of the casing string to secure the casing string in the well.

2. The method of claim 1 further comprising, while the cement is setting, disconnecting the tubular member from the second casing head and mounting control equipment on the second casing head.

3. The method of claim 1, wherein said second casing head has side outlets normally communicating with the throughbore of thesecond casing head, the step of ternporarily blocking said side outlets during the steps of introduction of cement into the well and of forcing of cement out of the bore of the casing string and upwardly around the exterior of the casing string so that flow of cement out through the side outlets is prevented.

4. Well completion equipment comprising: a first casing head having a longitudinal bore and an upper end; tubular control equipment having a longitudinal bore and a lower end secured to the first casing head upper end so that the tubular control equipment and longitudinal bores are axially aligned; means defining an interior, upwardly facing support surface within the first casing head; a second casing head having a longitudinal bore and means at the lower end thereof for supporting the upper end of a string of well casing; said second casing head being of such small external size as to be lowerable down through the longitudinal bore of the control equipment to said support surface; a lowering bushing having means thereon for disengageable securement to said second casing head for lowering the second casing head through said control equipment longitudinal bore, said second casing head being supported by said support surface; and means defining a plurality of arcuately spaced generally longitudinal passages between the exterior of the second casing head and said support surface opening at one end into the annulus defined between the exterior of the lowering bushing and the bore of the tubular control equipment and opening at the opposite end thereof into the annulus defined in the well about the exterior of the string of well casing, whereby during cementing operations cement introduced into the well through the bore of the string of casing to cement the exterior of the string of casing to the well can displace mud and other fluids upwardly through the passages means and upwardly within the annulus defined between the exterior of the lowering bushing and the bore of the tubular control equipment.

5. Well completion equipment according to claim 4 wherein said second casing head has means defining side outlets communicating at inner ends thereof with the second casing head longitudinal bore; said lowering bushing having a portion which extends downwardly into the second casing head longitudinal bore past said side outlets and seals with said second casing head longitudinal bore above and below said side outlets when the lowering bushing is secured to the second casing head whereby cement is prevented from escaping through the side outlets during cementing.

References Cited UNITED STATES PATENTS 2,207,255 8/1940 lesson et a1. 166-88 2,504,025 4/1950 Humason 16688 2,747,840 5/1956 Miles 16666.5 2,748,869 6/1956 Hager 16675 2,766,829 10/1956 Watts et a1 106-75 2,766,830 10/1956 Church 166-86 3,050,117 8/1962 Haber et a1. 166-665 X ERNEST R. PURSER, Primary Examiner. JAMES A. LEPPINK, Examiner. 

1. A METHOD FOR DRILLING, COMPLETING AND CEMENTING A WELL COMPRISING: MOUNTING A FIRST CASING HEAD HAVING A THROUGHBORE AT THE WELL; SECURING A TUBULAR MEMBER TO THE FIRST CASING HEAD SO THAT THE TUBULAR MEMBER EXTENDS AXIALLY UPWARDLY FROM THE FIRST CASING HEAD AND IN COMMUNICATION WITH SAID THROUGHBORE; DRILLING DOWN INTO THE EARTH THROUGH THE TUBULAR MEMBER AND SAID FIRST CASING HEAD THROUGHBORE FOR A STRING OF CASING; SEALING ATTACHING A STRING OF CASING BY THE UPPER END THEREOF TO A SECOND CASING HEAD HAVING A THROUGHBORE; SEALING ATTACHING A TUBULAR LOWERING MEMBER TO THE SECOND CASING HEAD SO THAT THE SECOND CASING HEAD DEPENDS FROM THE TUBULAR LOWERING MEMBER AND THE TUBULAR LOWERING MEMBER IS IN COMMUNICATION WITH THE STRING OF CASING THROUGH THE THROUGHBORE OF THE SECOND CASING HEAD; LOWERING THE TUBULAR LOWERING MEMBER, SECOND CASING HEAD AND CASING STRING INTO THE WELL THROUGH THE TUBULAR MEMBER UNTIL THE SECOND CASING HEAD RECEIVES SUPPORT FROM THE FIRST CASING HEAD; INTRODUCING CEMENT INTO THE WELL THROUGH THE BORE OF THE TUBULAR LOWERING MEMBER, SECOND CASING HEAD THROUGHBORE AND CASING STRING; AND FORCING THE CEMENT OUT OF THE BORE CASING STRING AND UPWARDLY AROUND THE EXTERIOR OF THE CASING STRING TO SECURE THE CASING STRING IN THE WELL.
 4. WELL COMPLETION EQUIPMENT COMPRISING: A FIRST CASING HEAD HAVING A LONGITUDINAL BORE AND AN UPPER END; TUBULAR CONTROL EQUIPMENT HAVING A LONGITUDINAL BORE AND A LOWER END SECURED TO THE FIRST CASING HEAD UPPER END SO THAT THE TUBULAR CONTROL EQUIPMENT AND LONGITUDINAL BORES ARE AXIALLY ALIGNED; MEANS DEFINING AN INTERIOR, UPWARDLY FACING SUPPORT SURFACE WITHIN THE FIRST CASING HEAD; A SECOND CASING HEAD HAVING A LONGITUDINAL BORE AND MEANS AT THE LOWER END THEREOF FOR SUPPORTING THE UPPER END OF A STRING OF WELL CASING; SAID SECOND CASING HEAD BEING OF SUCH SMALL EXTERNAL SIZE AS TO BE LOWERABLE DOWN THROUGH 